I have had insufficient opportunities to watch beavers for I have not seen one play icebreaker before. The beaver left its lodge in a bank and promptly encountered, what I think is called, grease ice. Grease ice is a later stage of freezing than frazil. The crystals have coagulated to form a soupy layer with a matt appearance.
The beaver just ploughed through the thin layer of grease ice.
It quickly acquired icy adornments.
While travelling (to the right), the beaver stuck its head below the grease ice and the flexible layer smoothly deformed over its moving body as if it were a bedspread atop a crawling toddler.
I remember canoeing on Anahim Lake once when there were ice crystals like snowflakes suspended in at least the top foot or so of water. Pulling the paddle through them produced folds – like pulling on velvet fabric. It was one of those magic like experiences one always remembers when so much else gets forgotten!